Governor



I taining means.

d Patented July 2O,`

covmmoa l Albert Kann. cleveland, oma

` ApplicationJune 2,' 1941, SerialNo. 396,338

(c1. zei-3) e 21 Claims. e This invention relates to a governoradapted for/regulating the operation (e. g: speed) of controllable apparatus and machinery. in accordance with changes in conditions of operation there- A of, and relates, more specifically, to a speed adjustment mechanism for a speed governor. The governorper se as illustrated herewith -is adapted for controlling the speed of a prirne `mover such as a Diesel 'engine and is very similarto that shown` in my Patent 2,219,229,` issued October 22, 1940. i f 1 `An object is generally to improve governors of the kind outlined above.

In the governing of aplurality of primemovers supplying aycommon load `as through direct driven alternating currentgenerators electrically in parallel by `governors responsive. to speed l changes of the governed units, it is necessary, in

order to obtainstabilityof operation and proper division of loadthat the `governors `allow slight decrease in speed of each unit in proportion to the increase in "load.v Such decrease in speedgoverning isA cornmonly called speed droop. Speeddroop is usually effectedor obtained as a function of governor-actuated. regulating oper-j` ationon theunits, as iswell known in governing. For successful variable vspeedparallel operationit is necessary that the slopeof the speed droop curvebe decreased in proportionj to decreasein'speed.` In other words whenthe speed is reduced say to one half normal the revolution "per minute decrease inl speed from zero load to vfull load should vbe approximately one half the e .speed droop at .normal speed. This results in substantiallyconstant percent speed droopfroml zero load 'to full load at any and all operating speeds.` For instanceL a speed droop of 10 R. P. M. at 1000 R. P. M. 4no load speed is 1%;

but the same speed droop in R. P.. M. in an engine set to run at 500 R.P. M is 2%; therefore it is necessary repeatedly` to recalibrate the speed droopgmechanism in order to obtain the same percentage of droop-at all speeds.

One cls 'iect is'to provide,. in combinatibn with speed setting means and "a speed droop obtaining means of a. governon'a means operating as a.y

function' of'lchange in speed settingtosvary automatically the operation Anotherobject is to 'provide a mechanism enabling the speed droop c'zharacteristic` of arggovretention of a constant percentage ofmspeed droop `in a governor over an entirerange of speed settings of such governor.` Another object ofthe present invention is to provide an improved adjustable mechanism for i obtaining `speed droop operation of la governor.`

'Anotherobject is to provide an improved control, or setting arrangement.J for d the weighing means of` a `governor which operates partly v through hydraulic `means;specia1m objects in this respect including: provision o"f improved means for adjusting a spring element of aweighin'g means (e. g. Speeder springof a speed responsive governor head) through the intermediary of a hydraulic motor (e. g. power head pis- 'through 'a hydraulic motor foi' initial` setting and automatically tomodify the adjustmentinaccordance with the regulation accomplished by the governor (e. g.' regulating servo-motor movement); provision for enabling yield in one direction in an operating connection between a pri-` `mary `adjusting means (e. g. manuallyor power" goperatedspeed setting shaft) and a controlvalve forl a hydraulic powerhead,`which valve isrsubton withappropriate control valve); provision of means enabling adjustment of such spring ject to becoming hydraulically restrained (oil l locked) against freer movement in said direcically operating mechanisms to be supplied with Other objects4 andthe nature of the problems solved by the present invention will 'appear later herein. Y e -In the drawings, Fig. 1 is aj generally `,central 'vertical sectional view of a governor incorporat- Il ing the invention in one form (plane of section` d w indicated on Fig.` 2); Fig.`2 is-a` plan view of the d d governor' (partly inY section as indicated at `2--2 on Fig. 1) Figs. 3 and 4 are detail sectional views ofthe speed dr'oop obl ernor. to*` be adjusted as from zerospeed` droop setting (isochronous operation) topther settings in which a governedprime mover speed-will -d'e-` i partlfrom normal speed under load certainy .de-` sii-ed percentagesA of the normal speed, andl whereinthe percentage 4of departure will b'e automatically recalibrated in" accordance with changes-in speed' setting over the entire range of speed settings obtainable with thegovernor. Afspecific object to `provide for continuous 1- Dieselengine). but without intent'to limit the inl vention 4tothat use- 'Ihe governor mechanism generallymay be made responsivento "any force resultant `other than'speedas well known in hggnf i 1 f as indicatedrespectively at 3` 3 on Fig. 1 and t-I on Fig. 3; Fig. 5 is a fragmentary view similarltothe upper portionlof Fig. 1 but awith the e 45 various elements in positions different from thosey in` which shown' inFlg. 1.` Fig.` 6 is a @schematic perspective view showings. modified Amechanism for obtaining speed droop and continuously recalibrating the percentage of speed droop in .accordance `with ldifferent speedfsettings, and Fig. 7 isa sectional `detailview taken i asndicated at 1--1 on Fig. 2 showing the servo- Acheck mechanism in "one form. i

e The invention willbe described` onlyas x ed tofregul'ate speed of a prime mover (e. g. a

tion, andfprovision fori-enablingallfthe hydraul- `hydraulic fluid from a com mori souree in a `compact self-contained governor unit.

adapt-.

GOVERNOR MECHANISM GENERALLY Referring particularly to Fig. 1, I is a base or adapter by which the governor is mounted 'power case; 4 a speeder case surmounting the*- power case and servo-motor. block, and 45 a detachable cover for the speeder case. The above .parts may be metal castings suitably machined and tted together with fluid tight joints.

For coupling thegovernor to a rotary part of a, machine to be governed (e. g. a Diesel engine) a shaft I may extend into the base I, supported as by suitable bearings II therein and passing through an oil seal,` not shown, to the top side ofthe base where the shaft is suitably connected toa gearelement I3 constituting one element of a gear pump.

The cooperating gear element is suggested diagrammatically as at I4 in dotted lines. The gear pump operates continuously, during rotation of the shaft I0, and cooperates with spring loaded accumulators (not shown) to maintain operating fluid at constant pressure in la system of ducts including bores I5, I'and I1 in the power case. l

'Hydraulic ,fluid supplied to and maintained at the bore I1 under constantpressure is controlled by operation of a pilot valve (plunger 20, sleeve 2 I and other elements to be described i later) to effect movement of a servo-motor piston 22 in the proper direction to regulate' the speed of the engine and to perform vother operations aswill hereinafter appear. Fluid is suD- plied to the pump from a supply sump S partly in the power case and partly in the Speeder case, essentially in the manner shown and described in the patent identied above (Figs. 1, 2 and 4 `munication `with the constant pressure space I1.;

and the ports- 28 in communication with the sump S.. 'I'he ports 34, through the duct 35, sup--V ply hydraulic fluid to the space 36 below the piston 22. i

Theports 21 .of the sleeve which arel normally Iblocked'by the land 25. communicate freely .at

all times with the servo-motor cylinder space 31' above the piston 22 through a duct 38 in the,

servo-motor block, which duct constitutes an extension Yof the bore I1. The reduced trunk portion 39 of the servo-motor piston slidably closes the upper end of the servo-motor cylinder and reduces theupperefectiye area of they servomotor piston relative/to its lower effective area, so that, with' the same pressure admitted to the cylinder above and below the piston, the latter' moves upwardly. Thevpiston has a power condownwardly from its normal (illustrated) position, the land 25 opens the space 32 inside the valve sleeve 2/I and around the neck 29 to communication with the high pressure source at the bore I1, whereupon constant pressure from thel bore I1 is admitted .to the duct 35 and delivthereof), Normal iluid level is indicated at L herein. The supply inlet of the pump (space I8, lowery part of Fig. 1) communicates with the power case portion of the sump; and inlet and outlet valves (examples at 23 and 24) cooperate as usual with the pump gears, pump chambers and inlet'and outlet ducts. accumulators may be located in the power case at opposite sides of the bore I6 and communicate with said bore as through cross channels in the under side of `the power case. One such channel is indicated at I9 (lower left, Fig. l). The accumulators maintain uniform pressure in the ducts I5, I6 and I1, and in the event of overdelivery by the pump, excess iluid being dis--v 'The pilot valve sleeve 2I is tightly iltted` into a central vertical cylindrical .bore in a `central portion of the power case which com.-

pletely .surrounds the valve sleeve. The valve sleeve has'a cylindrical. axial bore 3I which is open at both ends of the sleeve and, in which main -land portions 25 and 26 of the pilotl valve plunger are slidably tted and enabledto rotate while maintaining respective lateral Aports 21 and 28 respectively, of the sleeve ynormally sealed. A necked portion 29 of the valve plunger interconnects the two lands; and the space 32 inside the valve sleeve, formed by the neck and adjacent wall of the sleeve, is constantly open tocommunication with a duct 35, partly in the The spring-loaded ered to the lower side of the servo-,motor piston causing the latter to be raised due tothe area diierential of said piston, increasing power input to the engine. i y

When the pilot kvalve plunger is raised, the

land 26, by opening the ports- 28 to communication with theinterior of the valve sleevev 2|,

dumps operating fluidfrom the servomotor l cylinder lbelow the piston tothe 'sump through the duct 35, valve sleeve space 32 and ports 28;

r and constant pressure from theboresIT through tion of a fly-ball mechanism Ell including a Speeder spring 5I and fly-balls 52 pivoted on a rotary ball head A53. The inner rounded .end

portionslof the ily-ball arms 5I bear upwardly on the lower smooth face'of a thrust ring member 55 rigid'with the4 pilot valve plunger, tending to raise the plunger as the speed of the' engine increases; but (e. g.), so long as the load on the engine Aremains constant at a given setting Lof, the speeder spring, the downward force of the spring on the pilot valve plunger balances the upward force imposed by the ily-balls land holds said valve plunger against vertical movement.

` lower face of thrust member 55 ordinarily causes the pilot valve plunger .to rotate with the ball head during the entire operationl uf the governor. The spring is held against rotation at its upper end by an adjustable Speeder device .55'. supported as willjbe described later: and the lower end of the spring rests'on and is connected to a thrust ring. 5l. An anti-i'ricticn4 l bearingassembly' betweenthe thrust the pilotv valve plunger` enables the pilot valve l l When load on thefengine drops, thel move voutwardly, thus raising "the pilot valve ring and applied bythe spring.`

'Ii'he b al1jhead55fisjournaledfor rotation onv `a reducedl upperyend portion 58 of fthe piloti plungertc turn freelyznotwithstanding the pres-i` -va1ve sleeve 2f; a depending hub` portion 59 of i` the ball head, which `surrounds said portion .58 "lof the sleeve, has gearteeth (inland, as suggested diagrammaticallyin Fig. l (dotted lines) the teeth `rnesh'withJ a driving gear 6I on-'a ver` ticalshaft 62 the'` lower end of whichmis drivinglyvrigid with the Dump gear 14.1 The ball head" may be extended upwardly as'bya` shell 63 around `the fly-balls. i `Isochronous` operation" of'the governor requires primary and secondary compensation, as is well known., Thesystem shown herein is essentially .i the same as that of rthe above identied patent.

`Primary compensation is effected" hydraulically slotted head ss to enable adjustment as bxfmeahs l Y threaded to the sleeve 65 and has `for( example aof a screw driver.

Upon increase of load, `re

movement of the servo-motor piston moves` iiuid inthe compensation iluid duct 1U, raising or tending to raise the receiving compensation pisi ton 15, thereby to restrain the lowering' movement ,of the pilot valve.' `Secondary compensation `(leakage through `the restriction attheneedle va1ve51) removes the restraining action `ofthe f compensation piston 15 on`th`e pilot valve plunger as a` function of servo-motor piston movement;` f

and n restrains the axial movement' of i the pilot valve ini its operation to initiate movement` of the servo-motor piston, thus preventing overtravel of `said piston` both Vin reducing` an d increasing power input `tothe engine.` l

l as theV speed is brought backf.to normal; but the directionof fluid leakage is reversed. Fluid `from the duct 1n into the sump.` t

` "'I'hve" above described arrangement isgenerally the sarrefasthat oi.fmyP.atent 2,219,229 andthe operationthus far (isochronous governing oper-f fatiori) "isalso essentially thelsame asin said pat Eor` primary compensation, iiuid'is `moved iti a compensationiiluid ductglo which extends 4through various parts essentially the `same as 1in my said patent;` A hollow, piston 1I fixed to the upper end of the servo-motorblock 3 operates in "an` axialbore- 12 of the "trunk portion i3!!` of the "servo-motor piston 22 so as to serve as-an actuating compensation pump -in .irnzsrcasing` and `def creasing pressure ata lspace 13 below the .pilot valve sleeve2| and withinthe closed lower end of the bore Sli-of theypower case.` `Theconripensa-` l tion fluid ductl is normally kept full of` operat;

ing; iluid from the sump, through lateralholes 64 `in a Sleeve G5 (above servo-motor) thebore" of` which sleeve `has restricted communication, `by l reason of `an" adjustable needle valve 61, with the compensation fluidfduct 1D at `the upper eiidof` the hollovfpiston 1I; The holes 64 are open outwardly to the'sump in the Speeder case. i i

ent.v l'

' SPEED ADJUSTMENT The speed setting of the governor is changed `by increasing or decreasingthe compression ofv the Speeder spring 5| which opposes `the centrifulfgal forcef acting on the-y-balls. The illustrated` l i mechanism for `changing speed is generally the Fig. 2); The `Speeder `device 55'; earlierfmensame as that disclosed inmy cof-pending applica`` l tion Serial No. 385,228,` tiled March 26, 1941.

` As shown ln Figs.` 1 and Zhereof, `a; speed ad#` ,iusting lever extends over the speeder epring `5|,` (diagonally of the Speeder case as viewedl in `tioned, comprises, as shown, an adjustable pivotal connection between the lever 80 and 4Speeder "springinl the` form of a blockl* (cylindrical sleeve) pivoted on aligned pins 82 carriedbvA spaced portions of the le er `and ascrew 83 `threaded into the blockan'd'bearing downwardly pli'mger. As'the pilot valve plunger is moved upwardly from its normally centered position; `initiy f ating a downward or power input reducing moves ment oi the servo-motor pistonpsuction en the iluid in the compensation fluidlduct' litends. to" evacuate the space `I3 below thev pilot valve sleeve.

This acts, hydraulically,A yieldingly to restrain the upward movement of the pilot valve plunger. by"

\ virtueof a receiving compensation piston ,15 con- ,v nected to `thepilot valveplunger as lb v means of a coil springl capable ofA imparting reversible restraining action onthe valve plunger `and capai` ble of causing the .piston 15 to turnwiththevalve .plunger in thevalve sleeve during `the entire op-V l erating period of the governor. `'Il'he.srmcebe-I on' the speedersprlng.: 'I'hescrew may `beloclred o in place in the block as by a jamb nutllabutting i Y the block. The screw adjustment `.compensates for slight variation -inlength andV scale of difler- ,entfspeeder springs, so that, in-,eachgovernon` the lever may occupy, substantially a single posi.'-

tion at a givenrspeed setting, irrespective of such` i l l il variations in springs.

i Oneend' portion of the leverll, in 'a governor l l which [is always to be used to return the governed engine to a set speed irrespective of load change. l l

(isochronous), would have, in etl'ect;'a ilxed pivot, 3

and the other end portion would swing up pr down tochange and set the speed. Speed setting lis, accomplished, as `in my oopending application,`

by` avertically acting hydraulic power head `85 v connected `with the'lg`:ft hand `end of the lever. i i The power headis controlled eithenby manually' operated means or'power'dnriven adjusting mech'- aism suchas a Selsyn moton` H `Powerjhead l therefor maybearranged as follows: l

wardly throughv acylinderclosure capi! h l.

. A` power head 'cylinder I6 `is formed -in d fleft hand lower portion of thespeeden` case l.` A` power `headplaton `"slides in 'the cylinder i andhas a hollow` power rods` extendingfupfhg an opening which sucablylreceives and g'uid s able. For this purpose theneedlevalve pin"r is sultingirr a lowering@l i l.rriovement of the pilot valve plunger, thereverse of the above describedaction takes place.V The i resulting upward or power-input-` increasing` leaks `T'he `power'headwlnd controlling mechanism end of the axial bore 90 constitutes a valve sleeve The k in which a follow-up valve plug 92 slides. plug has an adjusting stem 93 extending out of the top end of the piston rod bore 90. The stem for the entire lengththereof within the bore 90 is formed relative -to the wall of the bore 90 so as to enable hydraulic uid to be discharged freely upwardly through the bore past the stem.

- The upper end of the valve plug normally is in sealing relation to a lateral port 94 in the pis-` ton (or the rod thereof'asshown) which port communicates freely with the power head cylinder at the lower side of the piston, asat 95; but

a slight downward movement of the stem and plug unseals said port. The lower end of the into Ithe cylinder above the piston and a slight upward movement of the plug unseals the port 96. side of the piston being smaller than the lower The effective transverse area of the upper suitably mounted in the speeder case?parallell to the shaft ||V and at the l'right thereof (Figs..

1 and 2). One end of the shaft |08 (or both ends if desired) can extend-out of thezcase for connection with a primary adjustmentldevice or mechanism. One end of the shaft V|00 (lower part of Fig. 2) is shownas serrated for engagement with an operating arm (not'shown.) right hand end of the ba'r |06 is pivotally pinned to the arm v|01 at |09, and the. slotted end slidably embraces a pin which is verticallyad justable along the upstanding arm IMof the bell crank |00. By reason of the pin-and slot .connection atv betweeny the armv |00 and the bar `|06 the'angular motion of the power head operating arm |02 is infinitely variable, within the limits of the slot, with respect to the angular motion of the shaft |08. An operating arm I plug similarly seals a lateral port 96 which opens side (roughly half), the piston'will be moved upwardly hydraulically whatever distance the stem 93 is raised, and will be moved downwardly whatever distance the stem 93 is lowered. Until some force is Aapplied longitudinally on the stem the hydraulic fluid in the power head cylinder 86 locks the piston rod 8|!v in vertical position. When downward movement of the plug 92 uncovers the port 94 the released uid from I the power cylinder below the piston is vented along the stem 93 to the power case.

The power head piston rod A88 is pivotally attached to the speeder spring adjusting leverr 80 by a collar 95 xed to the rod and having aligned horizontal pins 96 engaging arms formed by a bifurcated portion 91 of said lever. This pivotal connection, incidentally, prevents bodon the shaft' los could thereby 'be given, the same angle of movement from lowest speed to highest speed notwithstandingfthe fact that in diierent settlngsof the pin in its slot greater or less speed range-would be possible.

To increase the range the pin' is moved toward the shaft |0|.

For increased 'speed adjustmentthe shaft |08 is rotated counterclockwise as viewed inFlg. 1.

At the start `of governor operation the-power head valve,is usually oil locked against ydownward operation; and because of the cornpresslble link connection constituted by the spring and slotted bar|06, the shaft |00 upon increased speed adjustment cannot bemoved (e. g. manu- Y ally) soforcibly as tostrain 0r break any part of the adjustment mechanism.

SPEED Dxoop ADJUSTMENT Speed droop operation of thegovernor is accomplished by gradually reducing the downward ily movement of the spring adjusting lever in a horizontal direction lengthwise of said lever, since the power head piston rod is substantially rigid and guided for vertical travel only. l y

The valve of the power head 85 (plug 92 and operating stem) requires but a small amount of power to operate it', and thus the power required'for changing speed, manually or by a. Selsyn motor, may be made independent of the variable resistance of the Speeder spring in opposing speed adjustment. The available hydraulic power from the constant pressure source is always more than adequate to overcome the force of the Speeder spring at any degree of compression thereof. Thus the power head is useful: v(a) in preventing lag on part of (e. g.)

a Selsyn motor due to resistance by the jspeeder spring, and (b) in preventing the Speeder spring from disturbing manually adjusted speed setting.

Power head operating mechanism For operating the power headvalve stem 98 there is provided,'as shown inFlgs. `1 .and 2, a bell crank |00 pivotally supported on a horizontal shaft |0| in the Speeder case. The bell crank has a horizontal extending bifuloated arm |02 provided with a pin and slot connection |03 with the upper endof the valve stem. An upstanding arm |04 of the bell crank has a compressible link connection including a'spring' |05 and slotted bar |00with an arm` |01, which latter is keyed vto a speedadjustment shaft |00 force ofthe speeder spring onthe pilot valve as the load on the engine is increased -and the servo-motor piston 22 .operates through the rod 40 in the proper direction to increase powerl input to, the engine (upwardly as herein shown).

This is accomplished by operating `on the 'right hand end of the speed adjusting lever 00, hereinafter usually referredto as the power lever'. The resultof reduction of downward pressure on the Speeder spring by thev power lever. incident to suchoperation of the servo-motor is to facilitate the operation of the fly-balls in'`v returning the pilot valve toward normal position following increase in load. Thereby the speed of the engine 'is' not returned to ynormal (as in isochronous operation of thegovernor) but is depressed anjamount determined bythe slacking ofl of eiective Speeder springpressure, just as though the speed setting were altered slightly by'the speed adjustment mechanism 8?-|08.upon application -of load to the en, g ne. l Located above the right nandend of the power lever 80 is a horizontal cross shaft |20 carried asfon aligned pivot bolts or pins `|2| in the .speeder case which -enter respective ends of the shaft as suggested in Fig. 2. The shafty has an" enlarged eccentric cylindrical` portion |22, (displaced to the right of the shaft center las shown) l A ring. |23 (speed droop eccentric) einbraceathe eccentric |2| and in oneposition of the ring (Fig.

4) va cylindrical outer surface |25 thereof is'con- .centric with the shaft; that is, the eccentricity of the ring surface |24 relative to the eccentric |22 'offsets vthe eccentricity .of the latter relative to the axis ofthe shaft |20. The ring |23, as shown The.`

in Fig. 2, canbelocked accurately various po-` "sitions on the eccentric |22, notwithstanding adequateclearance between the contacting cylin- Vdrical surfaces, by a lock nut `|25 (speed droop iock nuwwthreaded tothe shaft Iza/.1aed having a conical surface portion |26, bearing 'on a complementary surfaceofthe eccentric ring |23, and

a' conical surface |21 of the ring, bearing on a further enlarged conical surface portion" of the shaft l|20. "Beyond" the last mentioned-conical surface, the shafttis further enlargedto provide a. toothed wheel or pinion |28 concentric withthe `shaft axis and meshingwith rack teeth |29` enla verticallyslidable rod I 30 mounted in the speeder case and power cylinder block. The rod |30con statutes in @neet a tail rod forthe.servefirman@` j `piston 22, beingheldin `contact with the topface of the trunk portion 33 of the piston 22 bya spring |3larranged to b'ear downwardly yon the `rod |30. An annular strap |35,;(eccentric strap),l having relatively concentric inner-and outer sur`l faces,` rides the outer` surface ofthe speed `droopr Aeccentric |23 and is held in position thereon bespring by raisingthe right handend of the power lever 80 substantially in proportion to the amount of upward movement `of the servo-motor in cansi ing acceleration i. e. increased power input-.tothe governed engine;

The relative upward travel ofthe rack |29 and i, fthe loweringdof theright handendofthe power lever 80 throgh the portion of the eccentric strap A|35 which makesy contactwith the follower liZcd portion. 0f which `isfnearl'y a straight line.`

Theslacking o`ff or'rthe Speeder spring'of eaclfi` .001" results in a nearly. proportional reduction in' speed of the engine. Therefore, at any given speed setting of thelgovernorthe speed droopY from no loadtoa given full load will always be thesame percentage of the original `or normal f CoNrINoUs RscALraa'ArroN or SPEED Dacor "In-order that theamount of speed dro'op will tween a flange portion |34 of said eccentric |23 j andthe adjacent face of the pinion. Thefiange |34 can be knurled to facilitate-turning of the eccentric |23; for speed droop adjustment, and the adjustment can be limited by`a`pin and". slot l connection between the eccentric-|23 and the pinion. As shown a pin |36 projects horizontally 1 from the eccentric into an arcuate-slot |31 inthe pinion, which slot is concentric with the ecceni tric portion |22of the shaft |20. Intheposition ofthe pin |36a indicated in Fig. Li the eccentric mechanism'isset forzerolspeeddroop, since the outer surface of the strap is concentric with` the shaft |20 `and turning ofthe latter cannot affect the position `ofthe righthand end of the power lever 80. Thus `far` the` mechanism discussed under` Speed droop adjustment is sub- 'stantiallythe same as thearrangementshdwn in` .my copen'ding application identified .abovefbut U theeccentric strap corresponding to part |35 hereof was pivotaliy attached to the power lever. l;

In the present arrangement the eccentric strap |35 operates, in conjunction with suitable spring i means to holdv theright hand end of the power 'lever in thedesired position vertically of the;v

speedercase through. afollower lever |40 piv` oted tojone side of the speedercase 4gas on apin.

|4`|, said follower lever having aplanar top surface in Contact `with the straptothe left ofthel `pivot pin. Thefollowerlever hasfafleaf spring |42 `bearing to the leftv on `the eccentric strap |35, tending always to hold the follower lever in` ybe, for examplegthe same percentage of normal speed at considerablydifferentspeed settings of `the governor it lis necessary properly'to modify the action of the `speed `droop obtaining mecha` nism such as described above, Vwhfenever a dif; ferent speed setting is chosen. 4The mechanism p `described b'elow i`s for the purpose of recalibrat-"J -ing the speed droopV percentage to peserve the same eifective speed droop at allspeed 'settings o asof'the shaft |08. I

f The follower lever |40 (see FigslS` ande) lis generally horizontal `slot |43 extending ytothe l"eft` of the pivot `piri|4|.` The power lever, adjacent the speed` droop eccentric, is similarly bifurcated,`

. to the right of thepower lever generally, tofp`r0` i vide slots "|44`.. The two levers are oonnectedby,

to causea gradual slacking oifof" the lSpeeder `hifurcatedto provide, in effect,` a `parallelsided a common pivot pin |45 which slides horizontally in the` slots of-the two leversk If thepin |45 vis `shifted to` the-right from* the position in, which shownin Fig. 4 (same as Fig. `1) lthen raising ofthe follower leveras from its horizontalposif A i 45" Y alesser slacking off of the -speeder spring than if l theeccentric strap tion "byjiftin'g of the eccentric strap will 'cause` were to be raisedswithithe o pin `|45 in the illustrated position.l

` speed setting) and to the left as the power lever contact `with thestrap. The power ylever hasfal pin and slotdconnection with the followerY lever, `described below, so thatlthe effective `pivot of the power'lever is determined principally inac- ,cordance with the position of the followerlever."

If desired, in order that Vthe `peripheral suri faces of theeccentric strap |35 andthe ilange o `|34 ofA the speed droop eccentricmay be marked t `with a suitable `pointeri and graduations 'ndica`.t-` i "ingthe amount of 'speed vdroop adjustment ina suitable way the strap can be kept from turning as by the device |39, partly attached to the speedercase. l .I

Speed `droop operation of thel governorwlll be n :readily imderstcwd1f` it is borne mmiiid that, m fairy lpossible` set position of the eccentric ring |23, except that shown in Fig. 4', increased power.

` input'operation ofthe servof'motor piston 22 will,... through the tail rod rack of the servo-motor, 0p-

erate `on the. speed droop eccentric lmechanism "is lowered (to increasedspeed` setting) "a motion# subtracting lever and linkage mechanism is pro- (vided which bears a directly proportional rela- .Y

tionship 1to the speed "adjusting movementof the power lever, so that the movement of the pivot pin toward fand -away from the followerV lever pivot` is,` linearly,l t always 1 in the sameproper-x tion to the movement impartedfto the` upper `gend-of thespeeder springbythe power;lever.` p `Raising `offthe powerlever andlthe consequent shifting of the pivot' pinA |45 to` the right, Vtoward i p `the follower lever pivot, results in a diminution i of the "amount of slacking oil' of pressure on the\ Speeder spring incident to `upwaidmovement of the servo-motor piston 22,- raising` of the V`rack |30, and turning' of thek eccentric mechanismjin `thedirectionto raise thezright A hand end of the,powerxlevert` l As shown, the motion subtracting or `normalspeed-fdroop-dimlnishing mechanism comprises a bell crarikflMilonearm"` |5I of "which is adjust" yably connected,l as by a link |52, to the power lever at the lei'tofI the connection of saidpower `For sh'ftingthe interconnecting pivot `pin |45 tothe right as thejpowevr` lever isgraised byithe speed adjusting( mechanism 05-,-|08 (decreasing,`

connects the `power lever and follower lever.

Thereby the pin |45 1s shifted to the right as the power head 85 raises the left hand end of the power lever and vice versa. The ratio of movement may be adjusted, if necessary, by a pin and slot connection |51 between the bell crank arm and the link |52; and the position of the pivot-pin-carrying block |55 may also be adjusted, so as to change the effective length of the follower lever with reference to the eccentric mechanism and power lever by virtue of the threaded connection between' the link |154 and block I |55. The mechanism Ulli-|55 operates, as heretofore outlined, graduas regulation is effected. The arm |69 has an operating connection with the arm |12 (e. g short slot |13 so as not tobind) such that as the longitudinal movements of the regulating rod take place the rockshaft |66.is rocked to and fro.

.The rockshaft |68 hasa short arm |14, over.-

reachin'g the arm |63 and free therefrom, posi-y tioned to contact with and depress an arm rigid with the'lever |65 which, asstated above" is plvoted tothe ,arm |63 of thespeed adjusting l shaft outwardly of the speeder plug, the point of Contact between |14 and |15 being between the axis of the speeder spring and the pivot axis `As indicated by arrows on the drawings, movement of the speed adjustment shaft |60 and its arm |63 clockwise sets'the governor for higher speed; counterclockwise lower speed. The rodr 40 of the servo-motor moves to the right for acally to reduce'slacking off of speeder spring pressure, incident to speed droop, as a function of clockwise or speed decreasing movement of the speed adjusting or power lever 80.

In Fig. 5 'the speed droop eccentric |23 has been turned 45 counterclockwise as evidenced by the relation'of the pin |36 to the ends of the slot |31. Initially this depresses the follower lever |40 about the pivot center i4| and thereby the right hand end of the power lever, so that to set the governor for a particular speed the movement of the power head would vary from that effected in the Zero speed droop setting, as will be obvious. As th'e tail rod rack |29 of the regulating servo-motor piston 22 is raised, during acceleration, the crank action of the eccentric mechanism is vto raise the` follower lever |40, that is to allow the lever |50 to be swung clockwise about its pivot into a raised position.

Automatic recalibration of speed droop percentage at diierentf'speed settings 'can also be accomplished with the arrangement according to Fig. 6 described below. The lever lengths are distorted for illustrative purposes, i. e. not drawn to scale.

In Fig. 6, the shaft |60 is adjustable to change speeds, as by a Selsyn motor through a gear segment and pinion indicated at |6| and |62 respectively, drivingly connected to the shaft. The

celeration of the engine; leftv for deceleration. In the initial position of the regulating rod 40 (low power input position as to the engine). the arm |69 will have been turned by the arm |12 through the slotted connection |13 therewith until the arm |14 of the rockshaft makes contact with the arm |15 of the lever |65, thereby holding the latter against upward i. e. clockwise movement,preserving a certain amount of downf ward pressure onthe speeder spring.

` As the shaft |60 isturned clockwise to adjust the speed setting'rto the desired point, the arm |10 of the shaft |60 raises the arm |12 and shortens the effective length of the arm |63. Thus as the. regulating rod moves to the right,

`during,v acceleration, the short arm |14 on the j rockshaft |68 lifts and permits the shorter arm of the lever |65 to slack off on the speeder spring to'effect a predetermined percentage of speed4 droop. Butat a lower speed setting the arm |12 will not have been raised so high along the arm |69 and therefore the same amount of movement of the regulating rod would not then slack if quite so vmuch on the speeder spring. Th lower speed settings, while the subtracting movement ef the1ever system lss, |14, |15 inrespeetto the setting of the speeder spring adjustment would be as much in distance unitsas at any other speed settingsneverthelesjs, with the proper shaft is turned clockwise to increase speed and carries anarm |63-journaled in the speeder case, y

which, ordinarily, would be pivotally connected to the speeder plug 83 of the speeder spring (not shown, but arranged substantially vas previously independent clockwise rotation of the lever |65.`

Coaxially of theshaft is a free rockshaft |68 to which, as beyond one end of shaft |60, a

depending arm |69 is connected. The shaft |60 has, drivingly rigid therewith; an arm |10 extending generally horizontally opposite the direc- 4 tion of extentv of the arm |63 oi said shaft. AThe arm |10 is connected, as by a link I1 I, to an arm |12, one end of which latter arm is pivotedto the regulating rod 40 of the servo-motor pistonv 22. 'I'he arm |12 extends generally parallel to the regulating rod and is moved bodily lengthwise lever arm ratios, the percentage of speed droop would be approximately the same as in such other speed settings..

Speed droop percentage adjustment `can secured with the arrangement according to Fig. v6 in' a variety of diifere'ntways; for instance vby changing the relative effective lengths of the As shown, each arm has aV series of holes (|11-in arm |10 and |10 inarm ,|12')/ at any onev of which the link |1| can'be arms |10 and |12.

pivotally connected. Thus, lengthening or shortening of the arm |12 relative to the arm |10 will modify the speed. droop percentage at agive running speed of anengine.

The device described above is shown in simplied form for illustrative purposes. If extremely accurate recalibration 'for all speed settings were l desired a geometrical progression cam mechanism, or its equivalent, could be lsubstituted in place of thel link and lever connection between the lever arms |10 ,and 12.

f AU'rouA'rIc SHU'rnowN Fig.- 1 shows a mechanically .acting arrangement byA which the speed adjusting shaft |00 can be caused toetlect completeshutdown of a Diesel engine regulated by the governor in.

atl

o o l I {2,324,515} event release of all pressure on the speeder 'spring is lnsuillcient to accomplish this. o The 'l tending substantially horizontally therefrom into1 overhanging relation to the' speeder plug element 83. Assuming theplug` element 93 is `a sleeve,

a iiexible chain I8| (e. g. bead chain) may extend from the arm |90 `down `through the `llug elementand speeder spring and have *a swivel connection |82 at its lower end Awith the pilot;`

fluid throughithe bore from thechainbr |93; the

valve plunger `as inside the hollow nut |93 whi'chI clamps theinner race member ofthe bearing 511` tothe thrustplate 55. The ""lowerend portion? 'of the chain turns freely inthe hollow nut sol o that the chain will not be twisted and brokenu Complete shutdown is accomplished when the i shaft |08 is rotated clockwise to such extentas;` to cause the chain to raise the pilotvalve`p`lunger` against the speederfspringpressure, thereby i dumping all the operating iiuid from the lower end of the regulating servo-motor cylinder by valving action of the valve plunger 20 already described. f r j #Instead of the `lexiblelinlr between the-arm |80 and thevpilot valveL plunger, a rodlsuch as *shownat |85, Fig. 5, could be usedinstead. The

f plunger being biased downwalrdlywbya light coil l Vspring 200 `reacting `upwardly against'an upper o wall 20| of thelbody.` An abutment scre'wZIlZ jjf threaded in` said wall 20| is, arranged adjustably ,to` limit upward movement. of the plunger `by engagement therewith as will be obvious. Com`-` municatingl with the chamber |93 is" a, restricted o outlet orifice 203 to the sump space of the Speeder casefor hydraulic iluid from the-s'pace`I9l above v i, i the servo-motor piston.` The outlet orice `may, f

be adjustable by reason of aneedle valve pin 204 aligned with the orifice and threaded intof the i body |90at 205. Fluid escapes-from theloodyV pastgtheneedle valve at asuitable lateral pas- Y i sage` 206 inthe body|90 beside the reduced tapered lower end of the needle valve pin.`

In operation, as the servo-motor moves fromA itsi lowered (shut down) position, fluid is forced through the duct` I9# raising the plunger |99 from the position shown-into a raised positioninwhich rod would have a` swivel joint, at least at one of y itsfends. Provision for longitudinal adjustment" of the link may com'prisethreaded nuts as atl "|86 (F,ig; 5) at the upper end of the rod |95.1T`h`ej rod should havea lost motion connection, either `with the arm |80 or with the connector |93 so that speed adjustment through theentir'e desired pilot valveplunger from /its normal position shown in Fig.` 1. 'i i `The mechanism described` -below isclaimed in my Patent 2,299,824 filed as a `division hereof and issued O`ct0ber27, 1942. ,r L

` range could be accomplished'with-out lifting. the` The servo-check, as previously stated, `preveerlts f the operation of the, regulating servoemotor pis-f ton 22and its regulating rod in power input in` creasing direction from being too rapid at crit` an adjusted rate V'appropriate to long life onpart ofthe engine. The check valve-|95 allowslun-` l of* throttle closure or fuel reducrestricted rate tion. f

During ordinaryfgovernor operation; because it takes a sudden :upward surge of hydraulic fluid through thecheck valve`|953y in order to close said valve,` the servo-check` mechanism` does not operate unless therate of increase `of fuel exc eds predetermined limits. Such limits may bev ried by increasing or decreasing (e. g.') the weight of ical `ranges of operation of the governed engine,` u

The device however allows the servo-motorand' regulating rod to move rapidlyin said direction `an adjustable distance and then dampsor checks the remaining travel in that direction. There is no damping in the power input decreasing direction. i l t fThe servo-check mechanism (Figs. 2 and '1)` comprises, in part, a hollow body |90 mounted on the upper 'side of the `servo-motor block 3 within the Speeder case I in convenientposi-L tion for communication ,with the space -|9I above the trunkl portion 39 of the servofmotor` piston. As shown the body |90 is vsecured to thea-block as Achamber' |93 on the un-I by suitable screws. l ,derside of the 4body |90` communicates with the servo-motor space |9| `through a` suitableduct |94 inthe servo-motor block. The

o o l hydraulic y space |9| has itsr'nainfexit'thriqllghfsaidduct |94; but `fluid is suppliedto saidspace' ythrougha check jvalve |95 showngatlv theright ofthe hollow `compensating ,piston 1| in Fig. f1. Fluid from the sump space` ofthe speeder case moves freely past the check` valve I95into the space` |9'I when the servo-motor piston lowers; wherefore f there` is `never any restraint on the speed de; creasing lmovement of the Y sevo-rnotor. g

` o Inside the body |-90,at the left Fig. 7,` is a rela `tively large vertical bore |91 in lopen communicationwith the chamber1|93 at the lower endof the ball in the check 'valve |95. or changing the character of thexoutlet passages around the ball.` i

j ,Attention ln called to` myprior application Ser. i No. 385,228 flledMarch 26, 1941, `in which certain* of` the matter claimed herein was originally `l. In combination with a normally isochronous speed governor` having adjustable speed setting means and other means` operative `to adjust a part of` the speed `setting `means to nobtain a desired percentage of speed droop on part "of the i machine to be governed during `operation ofthe l governer at one speed setting; of means ,operated fbfy the speed settingmeansand operative on said` othermeans to maintain `s'ubsftantially thesame ,percentage of speedfdroopl as the` speed Setting means is adjusted to` a different speed setting.

`2. In a. speed governor, speed `responsivecon-` trol meansrincludingri?.` Speeder spring and speed regulating means `actuated 'byjthe control i means', o i spee` setting` means'vacting on the spring" to` change speedpan ladjustable speed droop `control 'means operativelyconnected withthe regulating f "means in a manner to modify the speed setting in accordance,with certain positions of the lregulat- -lng "means, and (means operatively connected" with `the speed setting` means and actingon the.' "speed droop control means in suchmanner as; in l l eiect, to modify yautomatically the adjustment said bore. Theupper endjof tnefborefhas air vents |99. Acupshaped plunger |99 slidablyseals "the bore; |91 so as to blckthe exitof hydraulic` 'mechanism in a manner` progressively to modify thepercentage of speed droop as the speed setting a link adjustably connected with the pin and 'movable lengthwise of `the supplemental lever for initial adjustment of the location of the variable iulcrum.

9. A governor according to claim 5 wherein the speed adjusting lever 'is pivoted intermediately of its ends to a Speeder spring constituting a part of the speed control means, said mechanism includes a rotatably mounted differential eccentric in geared relatipn to the/regulator and capable of adjustment for zero speed droop and various percentages of speed droop action on the supplemental lever and thereby on the speed `admechanism is adjusted from low to high speed l settings.

4. In a governor, speed controlv means, a speed adjusting lever acting on said means' and means to swing the lever for primary speed adjustment, a speedv regulator controlled-by the speed control means for acceleration and deceleration of a governed machine, mechanism connected with the regulator and bearing on a portion of the lever in a manner tending gradually to counteract eiective movement of the lever by the rsecond mentioned means consequent upon ac-- celerating operation of the regulator, and variably acting lever mechanism connecting the rst mentioned lever and the rst mechanism in a manner to modify said action of the regulator on said lever in accordance with the motion imparted to the lever by the primary adjustment effecting means. w

5. In a governor, speed control means, aspeed adjusting lever acting on the control means, a

speed'regulator controlled by the speed control means for acceleration and deceleration Vof a governed machine, said regulatorhaving a part moved transversely of a portion of the lever, a

.supplemental lever on a xed pivot, mechanism arranged to cause said part to'swing the supplemental lever in a plane parallel yto the movement of the speed adjusting lever, a pin connecting said portion of the lattery lever with the supplemental lever and shiftable with reference to said portion and the supplemental lever as a Variable vfulcrum for the speed adjusting lever,.

and means connected to the fulcrum pin and actuated by speed adjusting swinging movement of the speed adjusting lever to shift the fulcrum pin toward and way fromy saidfixed pivot.

6. A governor according to claim 5, wherein the mechanism whichconnects said-part of the regulator with the supplemental lever is a bodily rotatable differential eccentric mechanism turned by said part and against one element of which eccentric mechanism the supplemental lever acts as a follower, and the eccentric mechanism is adjustable so that it has no action on y the follower, in one adjusted'condition of the eccentric mechanism, during regulating `movements of the regulator. 4

`7. A governor according to claim 5, wherein the means for shifting the fulcrum pin comprises a bell crank pivoted at right angles to the plane of swinging movement of'the speed adjusting lever and having arms linked to the latter lever and to the fulcrum pin respectively, and a part of the linkage isadjustable to vary the ratio between the swingingmovement of the speed adjusting lever' and that of the bell crank.

8. A governor according to claim 5 'wherein the means for shifting the fulcrum pin includes justing lever and .the end of the lever opposite the variable fulcrum has a iixed pivot in a power operated elevating device for setting. f y y 10. In a speed governor, a regulator part adapted to be moved in opposite directions for acceleration and deceleration of a governed ma-` chine, a speed setting lever Arockable about a fulcrum axis to adjust the speed at which the governed machine is to-operate normally, a supplel mental lever pivoted to the speed adjusting Ilever remotely of its fulcrum axisy and extending toward said fulcrum axis and adapted for. connection 'toy a speed changing element of the governor such as a Speeder spring, a rock shaft coaxial with the speed adjusting lever, an arm on the rockshait adapted to-bear on a portionof the supplemental lever 4in a manner tending to I turn it about its pivot toward such speed changy ying element, another arm on the rockshaft; a

member extending transversely of said 'other arm and parallel to the movement of theregulator party and connected therewith -so' that movementl of the regulator part shifts the memberlengthwise, a shiftable connection between@ ysaid other arm of the rockshaft and said member operable Vto 4impart rocking movementto the rockshaft and means operatively connected to the speed' setting lever and said member for causing a speed setting movement `to shift the connection between said other arm of theA rockshaft and said member in a manner to increase and decrease the swing of the rockshaft incident to a fixed movement of the regulator part.

1l. In a speed governor, speed weighing mech-v anism including a speed responsive element and Speeder spring and means controlled `jointly by.

said element and spring toeffect regulation, a Speeder case, van arm in the Speeder case extending over the spring and connected thereto,

a fulcrum in the speeder case furthe arm, a.

hydraulic power? head vcylinder in the speeder case, a power head'piston inthe cylinder having a hollow stem pivotally connected With the arm,

and a reversing valve for the piston coaxially thereof and having an operatingstem extending through the hollowpiston stem for operation'to adjust thespeed setting of the governor through the intermediary of the power head.

12. In a speed governor a centriiugally operable speed. weighing mechanism including a speeder4 spring, a hydraulically operated speed' adjusting mechanism operatively connected to the spring in a manner to increase and decrease its effective force for changing speed, an actuator 'valve for said hydraulically operated mechanism, which valve is subject to4 becoming hydraulically restrained'efroxrT-rapid movement 4in Ione direction, a speedsetting element, and anA 'operating connection between rsaid element and the actuator valvewhich connection is yielding changing l speed l 2,324,515 when moved in a manner tending to operate the` actuator valve in said` direction; i

13. In agovernor having afweighing mechanism including a spring, a reversible hydraulic power head having `a hydraulically i actuated plunger operatively-connected to the spring for` i varying its effective force, means to `supply hy-` draulic iiuid tothe power head, said means including an actuating valve plungermember on the power" head concentric `with the plunger Aoperatively connected to the springV at `one point thereof and 'operable to cause the powerhead plunger to move -in `opposite directions in direct proportion to movement of the valve member,

l an adjusting element, and a` yielding operating connection between the said adjusting element and the power-head-actuating 'valve plunger member.

14.\In a speed governor, mechanism for reg` ing element operatively connected to the spring tochange speed setting, a shaft operativelyconnected to the regulating `mechanism and turned thereby in a predeterminedfdirection consequent upon regulating operationsr thereof, and at speed droo'p'adjusting means comprising a diierential eccentric device on the shaft and operatively tric device being adjustable into a position `relative tothe shaft so thatturningof the shaft does not move the adjusting elementsand into other positions wherein turning movement ofthe shaft moves the element.` I

15. A vspeed droopadjusting means according n `30 connected to the adjusting element, said` ecceni i y ally adjusting the spring` automatically about* said pivotal connection inaccordance with predetermined regulating movements of the servo-- to claim 14, comprising acircular eccentric in fixed relation tothe shaft', anring having` a cir- .1 cular surface concentric ,withthe shaft and an# other surface complementary to the circular eclcentric and embracing the latter, means` connecting `the speed adjusting element to tne ring v along theilever for varyingthe effective `force of the spring, a hydraulic powerhead andoperating valve means therefor; said power head lbef ing connected to the lever atar'other point therealong for adjusting thelever and thereby the )spring initially to setwthelgovernor, and means operatively connecting a. movable element of the servo-motor to the vlever `at a third point there. along for additionallyadjusting the lever and spring automatically in accordance with predeterminedregulating movements ofthe servomotor. i Y

-1\9.` In a governor, a hydraulicrelay including a regulating ser'vlmotorfand reciprocably mov` able pilotlvalve, weighing mechanism including a spring connected to the valveifori operating `the g ivalve to control the servo-motor, an adjusting i lever operatively connected to the spring inter`` mediately of the ends of the lever for varying;

the eiective force of the spring, ja hydraulic` power head plunger and operating valve means y therefor, said lever being pivotally connected to the plunger `at a `point spaced from the aforesaid `connection-toward one end of the lever {orad- `justing the springvinitially to set the governor, n i

and means operatively connecting a movable elei ment of the servo-motor to `theleverat a point spaced fromthe` iirst mentioned connection "towardthe opposite end 4of thelever for additionf motor. f

tuating i pilot valve therefor, speedfweighlng i means including a speeder spring operatively at its circular surface and means for` locking` thev ring -in dierent `positions `on the eccentric.` 16. Ina normally isochronous speed governor,

ferent speeds, adjustable `mechanism for causing connected to the pilot valvea springt` adjusting lever` connectedintermediately of `its ends to the l spring, a. hydraulic lpowerhead pivotally con-` nected to one end portionl of theflever, control valve means for the power head for initialIyset'- i j ting the springv through the'intermediary of the lever, means constituting a movable fulcrum for speed "control means, speed regulating" `means,` .f the other end portion of the lever, and means i pperatively connecting the" servofmotor` to the the governor vto operate nonl-isochronously to f effect a desired percentage of speed droopat `one speed, said `mechanism operating on the speed .i

` control means as afunction of speed regulation,"

and speeddroop modifying means acting lon said adjustable mechanismA as a function` of setting of the speed setting means to obtain other speeds..

17; In a normally isochronous speedl governor',` speed control` means, speed .regulating means. speed setting means operatively connected to the speed control means and settableto-obtain ing'the governor to" operate non-isochronously 1 different speeds; adjustablemechanism for cansto effect a desired lpereritlteof speeddroop-at n one speed, said; mechanism `operating {o n the speed control means as a function of' speedr'eg- 'uni-.1011, and vspetti droop modifying means acti,

in g on said adjustable mechanism` as a function i of `setting of the speed setting meanslto obtain otherspeeds.`

able pilot valve, weighing mechanism for oper- 65? `tween the compensating pistonand cylinderdur` ing operation ofthe governorfor rendering the i governor sensitive to small speed czl'ianges,` and i 76 means operatively l connecting the` [servo-motor" 18. In a governor, a hydraulicrelay including f 9,-reguiat1ng servo-motor' and reciprocably mov n* fulcrum-constituting means in a manner auto-` matically to modify the speeder spring setting i in accordance with regulating movement oi the i servo-motor.` f

Y ,21; `In a normally isochronous `hydraulic-,relay governor comprising adjustable speedermecha-` ,nlsrriA including speed responsive means conynecte'd with relatively;` slidingtelescoping pilot i valve Aelements arranged to control aliydraulicv` n, n 'y l i regulating servo-motor,y .saidlgovernorhaving a i `servo-motortuated compensation*` system iny 1 cluding a re eiving compensation piston and ooj acting cylin er, one operatively `connected to the pilot valve compensatingly to bias the same dur ingl speed change; the combination of means varrimged to maintain `continuous relative `rotan tion between the` pilot valve elements and beand speeder mechanism, said last named means being adjustable from anime position u` .a i

spring connected to the valve, an adjusting lever i 

